1. Field of the Invention
This invention relates generally to the field of environmental remediation of storm water. More specifically, this invention relates to an improved modular filtration system for a storm water system.
2. Description of the Related Technology
Storm water that is created by storm runoff in heavily developed areas is typically channeled into storm drainage systems that eventually drain into nearby streams, creeks, rivers or other bodies of water. Paved surfaces that bear automobile traffic typically become coated with significant pollutants such as heavy metals and volatile organic compounds, both under normal traffic conditions and in particular when motor vehicle accidents occur. When normal rain or snowfall occurs, these pollutants tend to be swept away with the runoff storm water and eventually lead to contamination of the bodies of water that eventually receive them. Such contamination has become a significant environmental issue in many areas. In addition, a significant amount of sediment and debris such as bottles and cans tends to be swept away by storm water runoff. Some of the debris is heavier than water, and some of it has the tendency to float. Storm water filtering systems have to be able to effectively filter both types of debris, in both ordinary and elevated flow conditions.
Depending on the location of a storm water system inlet, the primary environmental concern may be pollutants or it may be sedimentation and larger debris.
Systems exist for filtering storm water runoff that are effective to some extent in removing debris from storm water and in removing certain other pollutants, such as hydrocarbons. For example, U.S. Pat. No. 6,080,307 discloses a storm drain insert that contains one basket for the collection of debris as well as a canister that contains a hydrophobic, compliant, oil-absorbent copolymer material that is said to be effective in removing oil from the storm water. Additional systems for removing pollutants such as heavy metals from storm water have been commercialized by Fabco Industries Inc., the assignee of this application.
The removal of sedimentation and larger debris from storm water requires a system that is simple to install and to service, since the collected sedimentation and debris will have to periodically be removed from the system.
A need exists for an improved system and process for processing sediment and debris laden storm water that is effective under all conditions and in filtering all kinds of debris, inexpensive to deploy and cost-effective to service.